Water heater



NW. 28, 1950 w, MARSHALL, JR 2,531,459

WATER mm Filed May 4, 194a s Sheejas-Sheec 1 Nov. 28, 1950 Filed May 4,1946 W. A. MARSHALL, JR

WATER HEATER '3 Sheets-Sheet 2 Va". A. MARSHALL, JR

WATER HEATER New. 28, 1950 Filedfiay 4, 194a -3 Sheets-Sheet 3 PatentedNov. 28, 1950 UNITED STATES new orricr Application May 4, 1946, SerialNo. 667,421

5 Claims.

The present invention relates to water heaters and more specifically toa type of small liquid fuel burning Water heaters designed for insertionin the line between an automobile engine cylinder block and a heatingradiator of the hot water type located within the drivers compartment orthe passenger compartment of the vehicle.

Although the heater shown and described is primarily for the purpose ofgiving quick heat in an automobile, it will be appreciated that theinvention relates more generally to hot water heaters and may also beapplicable to apparatus for heating other liquids.

Conventional hot water heating systems for automobiles usually comprisea heat exchanger or radiator located in the drivers or passengerscompartment of the vehicle and connected to receive hot water from theengine cylinder block and to discharge the water back to the cylinderblock in a closed circuit. Water heated by the engine is, therefore,passed through the heat exchanger or radiator and a portion of the heatis removed therefrom for heating the vehicle; radiation of this heatfrom the heat exchanger is commonly facilitated by an electric fan whichpasses air to be heated through or over the heat exchanger. However,with such a system no heating effect is produced until the temperatureof the water in the engine cooling system rises a substantial amount.

The heater of the present invention is inserted in the hot water linewhich leads from the engine block to a hot water radiator or heatexchanger which may be like that of the conventional system justmentioned; thus, all the water passing to the heating radiator must passthrough the device of the present invention. This device includes acombustion chamber in which liquid fuel, such as gasoline, is burned ata comparatively high rate so that heat can be transferred to waterpassing through the device at a rate of approximately 50,000 E. t. u. anhour. In this way the water passing to the heat exchanger or heatingradiator in the vehicle body is raised to a substantial'temperaturewithin a few seconds after the device of the present invention isstarted.

One object of the invention is to provide an improved hot water heaterof the type aboveindicated which is compact in proportions whileaffording a maximum of heat exchanging surface through which the heatgenerated by combustion in the heater is transferred to the water forcirculation.

Another object of the invention is to provide a novel hot water heateradapted to be manufactured at a comparatively low cost and by simple andconventional methods.

It is also an object of the invention to provide a novel Water heater ofthe type indicated which is safe and sure in operation and unlikely torequire any substantial attention for maintaining it in service.

Other objects and advantages will become apparent from the followingdescription taken in connection with the accompanying drawings, in

which:

Fig. 1 is a top View of a hot water heater embodying the presentinvention with a portion of the liquid connection broken away to showinterior structure;

Fig. 2 is a longitudinal sectional view of the heater illustrated inFig. land may be considered as taken substantially along the line 22 ofFig. l in the direction indicated by the arrows;

Fig. 3 is an irregular transverse sectional view which may be consideredas taken substantially along the line 33 in the direction indicated bythe arrows on Fig. 2.

The heater indicated generally by the numeral It comprises a conicalburner I2 located within a cylindrical inner shell 14 which forms thecombustion chamber for the heater with the large end of the burnertoward one end of the shell while the smaller end thereof empties intothe generally cylindrical space in the shell M. The shell [4 togetherwith a concentric larger sleeve it forms an inner water jacket [8 whichis closed at its ends means of annular flanged rings 20 and 22 solderedor brazed to the cylindrical sleeves l4 and It. This inner water jacket18 is surrounded by an outer water jacket 24 spaced therefrom andcomprised of a pair of generally cylindrical concentric spaced sleeves25 and 23. At the bottom of the heater the inner of these sleeves 26 isformed to provide a depressed cone 39 which is brought into contact withthe sleeve Hi, this depressed cone being punchedto provide a circularopening, through which a portion of the metal of the sleeve I6 isextruded and rolled over to form a circular seam 32 around the opening,which provides communication between the outer water jacket 24 and theinner water jacket 18. To prevent leakage, this seam is soldered. At thebottom ofthe heater this opening or passage is indicated by the numeral3i while at the top of the heater a. similarly formed passage isindicated by thev At the end of the heater opposite the burner l2, theouter water jacket is extended to form a re-entrant portion by means ofinner and outer cones 38 and 40, respectively. As will be seen in Fig.2, the inner cone 38 is rolled over near its outer edge to provide acylindrical portion 42 which is soldered to the end of the sleeve 26.Similarly, the outer cone is rolled over and soldered to the end of theouter shell 28. In order to space the cones 38 and 40 a proper distanceapart to provide a water jacket, these cones near their centers areprovided with mutually abutting extrusions 44 and 46 which prevent thecones from approaching each other more than a predetermined distance.Similarly, extrusions 48 are provided in the outer shell 28 so as tospace this shell from the next adjacent shell 26.

At the burner end of the heater, a flanged ring 49 acts as a cap toprovide a closure for the end of the outer water jacket space 24 whileastepped cup 50' closes the space between the shell 26 and a cylindricalbaffle 52' which acts to prevent products of combustion from flowingdirectly from the burner to the exhaust connection. The central portionof the cup 50' also acts as the closure for the back of the burner l2.

Near the bottom of the burner l2 the closure cup 50 is provided with apocket 54- into which liquid fuel flows by way of a tube 56 and fitting58. This pocket also is equipped to receive an igniter 60 of the hotwire type energized through an igniter wire 62. The igniter whenenergized acts to vaporize gasoline or other liquid fuel in the pocket54 and subsequently ignites the com- I bustible vapor to start the firein the burner l2. After the fire has been started, the igniter may bede-energized. Air for combustion is introduced through a tube 64 whichenters the burner tangentially at the top thereof. This tube extendsthrough bafile 52 and the shells 2B and 28 forming the outer waterjacket 24. Outside the heater case it is bent at right angles and isconnected to the outlet of a centrifugal blower 66. This blower isdriven by a small electric motor 68' which is secured to the heater caseby means of a suitable bracket 10.

When the burner is operating, products of combustion flow from theburner l2 into the cylindrical combustion chamber formed by the innersleeve l4 and heat the latter. Heat is therefore transferred to thewater within the jacket H3. The hot products of combustion also flowagainst the conicalsurface 38 and heat the water jacketed between thiscone and the outer cone 48. After transferring a considerable portion ofheat to the water as above indicated, the products of combustion flowaround the end of the ring 28 and between the shells l6 and 26, therebytransferring more heat to the water within the jacket 18 and to thewater within the outer jacket 24. At the burner end of the heater theproducts of combustion are collected within the annular plenum chamber12 and pass outwardly through 'then being soldered in place'to insureagainst leakage. Water flowing into the heater, there fore; directlyenters the outer jacket 24 and passes into the jacket l8 by way of theopening 34. At the top of the heater the outer water jacket 24 isprovided with an outlet opening 88 directly opposite the passage 36which communicates between the inner and outer jackets. The metal aroundthe opening 88 is extruded outwardly and rolled over to form aconnection with an elbow fitting 82, the joint being sealed with solderto prevent leakage. Elbow fitting 82 is connected at its outlet by meansof a rubber sleeve 84 with an adapter 86 which in turn is connected to arubber hose 88 which carries the hot water away from the heater. In aconventional installation the hose 88 will be connected to aconventional hot water radiator located within the drivers or passengerscompartment. In order to control the flow of liquid through the system,the hose connection 84 contains a liquid thermostat 90 which may be ofconventional type and which opens at a predetermined temperature, as an.example, degrees F.,so asto' permit water to flow through the system aslong as: the water temperature is above this predetermined-level and toinhibit flow through, the system until this. level has been reached.

The top of the elbow. fitting 82 in a position directly opposite thepassages 8e and 36 is provided with a threaded boss 92 to receive thehead 94 cf'a thermostatic bulb. 9 6 which is connected by means of acapillary tube 93 with a pressure responsive control switch mechanism at18-. Whenever, with this system, the temperature of the buib as rises,the vapor pressure therein will rise, thus raising the pressure. in thetube 98 and in the pressure responsive switch we. The bulb 98: containsa quantity of fluid with proper vapor pressure. characte'rististics toopcrate within the temperature range desired. The tube 28 is connectedto actuate the switch mechanism at we and this device controls thecircuit for the igniter fiilan'd also controls the fuel feed throughsolenoid valves lit and HE. When combustionhas been started and amoderate temperature has been attained in the vicinity of the bulb 96,the igniter is switched off. At a somewhat higher temperature the fuelfeed is restricted by opening the circuit of the valve H4 and allowingthis valve to shift; from full flow position to restricted flowposition; At 'a predetermined maximum temperaturethe valve H5 isde-energized and allowed to close, cutting off the fuel supply andshutting down the heater until the temperature at the bulb t t-drops toapredetermined value. This control cfthe heater by means'of thetemperature responsive'b'ulb'llt and the switch mechanism lee-"forms thesubject matter of the application of John H. Leslie, II, and William A.Marshall, Jr., Serial No. 636,743, filed December 22, 1945.

It will be noted that the construction of the heater is so planned as tofacilitate'assembly and to employ conventional operations in theformation of the parts. The cylindricalfshell i6 and the sleeve 55 whichform the inner water jacket are of equal length'and' are connected attheir ends by the annular channel-shaped members 28 and 22. The cylinderI i fits snugly around the inner flanges of these channels while thecylinder It fits snugly 'wi thin" the outer flanges of the channels sothat the channels serve to space the cylinders hi and it from each otherand to maintain them in coaxial relation. Similarly the channeleshapedring '49 on ects and spaces the inner cylinder 28 and the out-e13cylinder 2:} of the outer water jacket'at one end.

At the end of the heater opposite the burner l2 the cylinders 26 and 28are closed by the end walls 33 and 40 which fit telescopically over theends of the two cylinders, respectively, with the truncated conicalportions projecting into the combustion chamber. The mutually abuttingbosses 44 and "i6 centrally located in the flat end portions of theseend walls 38 and 49 and secured together as by welding serve not only tospace the truncated conical parts from each other but also to centerthem with respect to each other so that at their telescopic connectionswith the cylinders 25 and 28 they maintain the cylinders in properlyspaced relation and keep them coaxial. To some extent, of course, thisspacing of the two walls of the outer water jacket is supplemented bythe extrusions or bosses 4'18 shown in Fig. 2.

While there is shown and described herein certain structure embodyingthe invention, it is to be understood that the invention is not limited"thereto or thereby but may assume numerous other forms and includes allmodifications, variations and equivalents coming within the scope of thefollowing claims.

I claim:

1. In an internal combustion heater, a cylindrical shell forming acombustion chamber, a sleeve surrounding said shell and spaced therefromto form an inner water jacket, annular members closing both ends of saidjacket, a burner disposed at one end of said shell and adapted todischarge products of combustion toward the opposite end of the shell,an outer water jacket surrounding the inner jacket and spaced therefromto provide a passage of annular cross section for products ofcombustion, said outer jacket having an end wall which in cludes are-entrant portion extending around the said opposite end of the shellof said inner jacket in spaced relation thereto and having a truncatedconical form projecting into the combustion chamber and tapering towardthe burner, the re-entrant end portion of the outer jacket within thecombustion chamber including flat circular walls formed with mutuallyabutting bosses which space them apart to provide a water space incommunication with the remaining space of said outer jacket.

2. In an internal combustion heater which includes a cylindrical shellforming a combustion chamber and a burner disposed at one end of saidshell, a Water jacket spaced from said shell to provide a path forproducts of combustion, said jacket comprising an inner cylinder and anouter cylinder, an annular member of channelshaped cross section closingone end of said jacket, the inner flange of said channel fitting snuglywithin the end of said inner cylinder and the end of the outer cylinderfitting snugly within the outer flange of said channel, and an end wallfor the opposite end of each cylinder fitted telescopically over thatend of each cylinder and including a re-entrant portion extending aroundthe corresponding end of the combustion chamber shell in spaced relationthereto, said end walls being of truncated conical form nested in spacedrelation and projecting into the combustion chamber toward the burner,and the smaller ends of said truncated conical parts having mutuallyabutting bosses secured together and holding said parts into axialrelation.

3. In an internal combustion heater, a cylindrical shell forming acombustion chamber, a sleeve surrounding said shell and spaced therefromto form an inner water jacket, annular members closing both ends of saidjacket, a burner disposed at one end of said shell and adapted todischarge products of combustion toward the opposite end of the shell,an outer water jacket surrounding the inner jacket and spaced therefromto provide a passage of annular cross-section for products ofcombustion, said outer jacket including an end wall which extends acrossthe end of said inner jacket and combustion chamber opposite that atwhich the burner is located, said wall being spaced from said oppositeend of the inner jacket to provide a connecting passage between thecombustion chamber and the space between said jackets, means forming anexhaust outlet leading from said space, and means connecting the innerwall of the outer jacket to the outer wall of the inner jacketcomprising an annular portion pressed out from one of said wallsextending toward an opening in the other and connected to the rim ofsaid opening in watertight relation, said connecting means providingcommunication between the inner and outer jackets and maintaining thespace between them as a passage for the flow of products of combustion.

4. In an internal combustion heater, a cylindrical shell forming acombustion chamber, a sleeve surrounding said shell and spaced therefromto form an inner water jacket, annular members closing both ends of saidjacket, a burner disposed at one end of said shell and adapted todischarge products of combustion toward the opposite end of the shell,an outer water jacket surrounding the inner jacket and spaced therefromto provide a passage of annular cross-section for products ofcombustion, said outer jacket including an end wall which extends acrossthe end of said combustion chamber opposite that at which the burner islocated, said wall being spaced from the corresponding end of the innerjacket to provide a connecting passage between the combustion chamberand the space between said jackets, means forming an exhaust outletleading from said space, a connection between the inner wall of theouter jacket and the outer wall of the inner jacket comprising anannular portion pressed out from one of said walls extending toward anopening in the other and connected to the rim of said opening inwatertight relation, a second and similar connection between the innerwall of the outer jacket and the outer wall of the inner jacket locatedat the opposite side of the axis of the heater from the first mentionedconnection, a water inlet coupling secured in an opening inthe outerjacket opposite one of said connections, and a water outlet connectionsecured in an opening in said outer jacket opposite the other of saidconnections.

5. In an internal combustion heater, a cylindrical shell forming acombustion chamber, a sleeve surrounding said shell and spaced therefromto form an inner water jacket, annular members closing both ends of saidjacket, a frusto-conical burner disposed at one end of said shell andadapted to discharge products of combustion toward the opposite endthereof, an outer water jacket surrounding the inner jacket and. beingspaced therefrom to provide a passage of annular cross-section forproducts of combustion, said outer jacket including a first end wallwhich extends across the end of said combustion chamber'opposite that atwhich the burner is located, said first end wall being spaced from 'thecorresponding end of the inner jacket to provide a connecting passagebetween the combustion chamber and the, space between said jackets,means forming an exhaust outlet leading from said space, a steppedcircular end wall fitted within the end of said outer jacket oppositethat in which the first mentioned end wall is located, said burnerhaving a base adapted to be received over the step, in said steppedcircular end wall for supporting said burner inwardly of the said secondmentioned end portion of said outer jacket and the corresponding end ofsaid inner jacket terminating at a point inwardly of the innermost faceof said stepped circular end wall, and a cylindrical baffle fitted ontosaid step around the base of said burner and extending therefrom intotelescopic engagement with the 8 inner Water jacket for supplementingsaid jacket as a partition between the combustion chamber and theannular passage through which products of combustion flow from saidchamber to the exhaust outlet.

WILLIAM A. MARSHALL, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

